A conventional socket adapter is shown in FIG. 1 (Schematic Exploded View of a Conventional Socket Adapter) in which an insert holder 11 has two receptacles 111 at proper points for containing leaf copper conductors 21 of a power cable 20 connected to a power source. The receptacles 111 are separated by a separator 114. The insert holder 11 has plug-holes 112 on its front side and a passage 113 arranged for cords going through. When the leaf copper conductors 21 of the power cable 20 are fitted in the insert holder 11 which, then, is inserted in an exposed internal space 121 of a housing 12, a complete socket adapter will be obtained. However, such a socket adapter design has some shortcomings such as unsatisfactory waterproof protection, presence of a potential risk of short circuit caused by loose cords of the power cable 20 if the joint 22 between the power cable 20 and the leaf copper conductors 21 is not clamped properly. Furthermore, the clamped joint 22 of the power cable 20, after long term use, may be loosened or unclamped by an eventual foreign force, resulting in a power failure or electrical leakage, or damaged by undesired shocks. Therefore, it is really not an ideal design.
So, a socket adapter design is desired which is able to provide waterproof protection, high strength and excellent security.